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1. Introduction
Diabetic Foot Syndrome (DFS) is defined as a multi-factorial clinical triad of neurological, vascular, and musculoskeletal changes induced by diabetic peripheral neuropathy [1]. The overall prevalence of DFS, according to the International Working Group on the Diabetic Foot (IWGDF) Risk Classification System, is reported to be 51.8% in India; it is a common reason for hospitalizing patients with diabetes and its related complications [2, 3]. Biomechanical changes and foot deformity due to motor neuropathy; the loss of protective sensation induced by sensory neuropathy; and autonomic alternations, such as fissures, callus, b:union: contribute to the altered plantar pressure distribution and ankle kinematics of DFS. Accordingly, such conditions lead to an increase in the incidence of the generation of diabetic foot ulcers [4].

2. Case Presentation 
A 49-year-old male patient with a 10-year history of type 2 diabetes mellitus presented to a diabetic foot clinic. His chief complaints were frequent burning and pricking sensation on feet for 3 years. He was under oral hypoglycemic pharmacotherapy for 5 years. His demographic findings are explained in Table 1.

Besides, after providing an informed consent form, a comprehensive diabetic foot evaluation form was performed to obtain a detailed diabetic foot evaluation (Table 2).

This study was approved by the Institutional Ethics Committee of Kasturba Medical College and Hospital (IEC169/2019).
At the baseline, dynamic plantar pressure distribution (3-sec duration, 100 images per second, 100 Hz) and postural sway (30 sec 1200 images, 40 Hz, one parameter) were evaluated using WinTrack dynamic pressure plate (WinTrack, France). The 3-step gait protocol indicated good reliability, with Intraclass Correlation Coefficient (ICC) values ranging between 0.75 and 0.90 in gait parameters. He was instructed to walk on the platform at a reasonable pace. Three trials were conducted, and the relevant data were extracted and analyzed by WinTrack software. Photobiomodulation therapy (low-level laser therapy) was prescribed for neuropathic pain and symptoms. A scanning laser wavelength of 632.8 nm with the dose of 3.1J/cm2 (TECH LASER SS-1000, Technomed, India) at the plantar and dorsal surface of the foot (6 min each), the probe laser wavelength of 660 nm and 850nm (THOR Laser Pro, THOR Photomedicine Ltd, USA) with the dosage of 3.4J/cm2 by contact method at popliteal fossa (Figure 1)*3 min were implemented. Ten regular sessions of photobiomodulation were conducted. 
The LASER equipment was calibrated with a Laser Photometer Power meter kit. Customized insoles were recommended for redistributing the plantar pressures and reducing stress on the diabetic foot’s plantar surface. The insole was developed by FootBalance equipment. FootBalance medical insoles were applied for molding. It is a 1.2mm thick insole made with 4 layers. The outermost layer is a Durable top layer with an antibacterial coating. The middle layer is Comfortable, a high-quality shock absorption base layer. Initially, the study participant was requested to stand barefoot on the transparent mirror on the FootBalance platform and data analysis was conducted. Then, the study participant’s foot arch was kept in 3 functional positions; standing straight, knees bent 45° and standing with toes extension. Comparing their arch matching was performed by the closest type of medial arch type was selected. An appropriate foot size insole was selected and inserted into the heating rack. We placed the warm insole between the study participant’s foot and Fitpillow; subsequently, it was molded according to the arch and weight distributed evenly on both feet for 20 seconds. Then, a customized insole inside footwear was inserted (Figure 2). The reassessment was performed at the end of the fourth week to compare the pre-post changes of vibration perception threshold plantar pressure distribution changes and postural sway (Table 3).

3. Discussion 
The present study data suggested a change in various biomechanical parameters. In the right foot, a reduction of APP 11.9%, MPP to 6.5%; and in the left foot, APP 11.1% and 31.2%, respectively were detected. The total contact area of the right and left feet increased by 17.6% and 41.1%, respectively. The forefoot hindfoot ratio is also a predictor of developing forefoot ulcers; the higher the ratio, the higher the risk. The combined intervention has reduced the ratio of foot pressures [5]. Vibration Perception Threshold (VPT) is a sensory test to evaluate the extent of the loss of protective sensation in diabetic peripheral neuropathy. Values more than 20V were considered along with the inability to perceive 10gr monofilament for at least one point to be peripheral neuropathy. In the first 10 sessions, VPT has been improved from 32V in the right to 25V in the left to 9V and 7V, respectively.
Kinematic parameters were also improved from pre- to post-intervention; especially stride duration, gait cycle length, and double stance duration. This finding reflects that the gait pattern was improved. Furthermore, the gait alterations were reduced for better propulsion of the foot during gait [6]. Balance is also the main component altered in diabetic peripheral neuropathy. Postural sway is among the gold standard methods with quantifiable variables. Variables, such as CoP length, CoP Area, X, and Y-axis speed, Y-axis deviation, have significantly improved in the explored patient. CoP length revealed increased postural stability in the patient. This may be attributed to enhanced plantar sensory perception induced by elevated neural activity at the lower peripheral nerves.
In this study, we have explored static and kinetic spatiotemporal parameters. Moreover, kinetic and kinematic characteristics were examined by the biomechanical model generated in the gait pattern. Photobiomodulation therapy is a noninvasive non-pharmacological modality based on the principle of bio-stimulation effect. Thus, PBMT significantly improves sensory perception. The potential mechanism might be due to PBMT that may prevent motor cell degeneration; induce Schwann cell proliferation; boost neural metabolism, and increase myelination and axon regeneration [7, 8].
For individuals with diabetic neuropathy, custom insoles are frequently prescribed to offload high pressure from the Metatarsal Heads (MTHs) and other regions that reduce the risk of plantar ulceration [9]. Insoles provide the critical interface between the foot and the shoe; they also present the most effective approach to minimizing potentially damaging tissue tension on the plantar part of the foot along with outsole modification [10]. The Diabetic Feet Australia guidelines on footwear for individuals with diabetes also recommended the appropriate footwear with customized insoles can reduce the plantar pressures at the plantar surface of diabetic foot. It also highlighted the reduction of >30% in the region with the highest plantar pressure, compared to the same region of foot considered as plantar pressure d effect [11].

4. Conclusion 
Photobiomodulation therapy with customized insoles is useful in the redistribution and treatment of plantar pressure and gait kinematics. It should be extensively employed in DFS as preventive and treatment measures. However, this study was a case report, further detailed analysis and experimental study designs with long-term follow-up would help to strengthen this argument regarding the effectiveness of this approach.

Ethical Considerations
Compliance with ethical guidelines
There were no ethical considerations to be considered in this research.

Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors.

Authors' contributions
All authors equally contributed to conducting the study and drafting the manuscript.

Conflict of interest
The authors declared no conflicts of interest.

Acknowledgments
The authors would like to acknowledge the Centre for Diabetic Foot Care and Research (CDFCR), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India.


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